


Restart My Heart - (An Undertale Fanfic)

by AnnaRaeBanana



Category: Undertale (Video Game)
Genre: Action/Adventure, Alternate Universe, Alternate Universe - Angels & Demons, Angst, Angst and Hurt/Comfort, Attempt at Humor, Awkwardness, Badass, Bathing/Washing, Birthday, Blood and Injury, Blood and Violence, Brotherly Affection, Brotherly Angst, Brotherly Bonding, Brotherly Love, Canon-Typical Violence, Chatting & Messaging, Confessions, Crying, Cuddling & Snuggling, Dancing and Singing, Drama, Dreams and Nightmares, Emotional Hurt/Comfort, Emotional Manipulation, Family, Family Drama, Family Feels, Family Fluff, Feelings, Fights, Flashbacks, Flirting, Fluff, Fluff and Humor, Friendship, Hatred, Holidays, Horror, Hurt/Comfort, Implied/Referenced Self-Harm, Injury, Jealousy, LGBTQ Themes, Loss, Manipulation, Memory Loss, Memory Related, Mental Health Issues, Mild Language, Mind Manipulation, Misunderstandings, Multiship, Music, Mythical Beings & Creatures, Other, Pain, Panic, Panic Attacks, Past, Past Abuse, Past Lives, Protectiveness, Psychological Horror, Restaurants, Reunions, Royalty, Sad, Sanscest - Freeform, Secrets, Self-Esteem Issues, Self-Hatred, Shapeshifting, Soulmates, Supernatural Elements, Team Bonding, Team as Family, Teasing, Teenagers, Tension, Violence, War, Weapons, Weather
Language: English
Status: In-Progress
Published: 2019-10-27
Updated: 2020-08-30
Packaged: 2021-01-04 19:01:43
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 5
Words: 3,050
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21202511
Author URL: https://archiveofourown.org/users/AnnaRaeBanana/pseuds/AnnaRaeBanana
Summary: Do you believe in that which you cannot see?Nightmare Joku is a normal monster from a normal tow. There is no doubt about that. At least, that's what he thought. When Haloween brings an unexpected field trip, Nightmare and his friends find themselves caught up in a war between Angels and Demons.Yep. Very normal.***WARNING: MIGHT CONTAIN SCENES THAT TUG YOUR HEART, LANGUAGE, NOT FOR THE FAINT OF HEART, TALK ABOUT TOPICS SENSITIVE TO SOME PEOPLE AND OTHER THINGS.READER DISCRETION IS ADVISED.





	1. Introduction

**This story will be posted on all fanfiction sites I have an account in. They are all under the name AnnaRaeBanana, and no fanfiction I post on here won't be posted on those sites as well. A few things to note:**

**1\. _I don't have a Beta Reader for this story. That means everything written is my own skill and editing, which I don't know that much about. If you are a Beta Reader, and you like this story and want to help, then please contact me._**

**2\. _As for updates, I'm still working on them. They will be slow, though. I have two other stories, still in progress, so my time will be divided between those, this one, and more stories that I haven't published yet. School also started last month, so that will take up my time. I missed all of last grade; I can't afford for that to happen again._**

**3\. _And as in my other stories, please keep an open mind. _**

**Constructive Criticism, warnings about OOCness, warnings about plot problems and other things of this nature are all welcome. If you intend to be harsh, then please leave. I will not give you a warning after this. Other than that, please enjoy the story.**

**Your friend and writer,**

**AnnaRaeBanana**


	2. Angels and Demons

_Do you believe in that which you cannot see?_

_The kind of thing that the knowledge of has existed for as long as you remember, but never was proven?_

_Heh. Good. Then you will understand perfectly._

_You see, this all begins years ago. Before you were born in fact. And your mother. Your grandmother. Before hundreds of your ancestors walked this earth. It begins in a world that relied on a constant balance to keep itself from falling apart. In a world of people different from you._

_A world of beings that you would call Angels and Demons._

_Surprising, is it not? You would have never guessed that this revolved around these beings you hear about every day. You never thought they were real in the first place._

_We are getting sidetracked. Angels and Demons. Good and Evil. Two sides of a coin. A coin that can change its shape based on what one believes is true. Whether it be black and white, or silver and gold. Let us trust this base image, however. A slate which is neither true nor false. Good and Evil. If this is to be true, then we can tell who would be on either side, correct?_

_Angels are Good, while Demons are Evil. Simple and obvious. Only...we're wrong. It is more complex than that. Angels can be bad, and demons can be nice, but they cannot cross sides fully. They will always have that tie binding them. Unless it is severed, but few can do that. It would take an act impossible for them to do, and even if they manage it, they would need to be strong enough to deal with the consequences. Which is why it is common knowledge, but banishment worthy if caught attempting it._

_Trust me, I would know._

_Before, I was a leader. The general of light that set out to correct those lost. I would become their friend, help them get back on their feet, and they would forget me, telling me it was time to go back home. Now...now, I am forced to spend my days in the dark, feelings of betrayal lingering from a fight millennium ago._

_It hurts..._

_But I am not why you are here. No, you are here for them. The mortals who stumbled into a war of survival. I will not keep you, though we will meet again. Trust me._

_And a warning before you go and jump into unknown waters you think you know:_

_Pef'z zbyaz zlo Hexoba en Ocykhkrbkyg._

**Notes for the Chapter:**

> The ending is a cipher, yes.


	3. Act One: Memories Awakened

_I'll be good, I'll be good_

_And I'll love the world, like I should_

_Yeah, I'll be good, I'll be good_

_For all of the time_

_That I never could_

_\- '**I'll Be Good' by Jaymes Young**_


	4. Chapter One: Halloween

"Good Morning Mount. Ebott City! I'm your host Ace XXtha, and welcome back to this morning's segment of 'Chance Your Morning'! No, we don't do predictions, we just tell the news and give a few interviews. We know our name is misleading. Please stop commenting on it. Anyways, today is October 31st, and you know what that means! That's right..." He turns the car's radio off and sits back with a huff.

"I don't know why you listen to that show, Cross," He says, giving his driver friend a look as he pulls out of the driveway. "you know it's trash."

Cross laughs. "Hey now!" He says, meeting his look and turning his blinker on. "It's news, so of course it's trash. But it's also the only trustworthy news channel in the city. You know that, Nightmare."

Nightmare laughs as well. "True." They descended into silence they knew would last for the rest of the ride. Nightmare watches the buildings and trees pass by, silently judging the last-minute Halloween decorations and Halloween costumes.

He couldn't blame them though, everyone in the city didn't really celebrate Halloween. It was never popular, to begin with. They kept the holiday around and continued to do everything, but nobody seemed too interested. Whenever the day rolled around, everyone always got a bad feeling, like something bad was going to happen, but it never does. Except for the occasional normal crimes, there was nothing special about the holiday.

Nightmare never cared for Halloween that much either. He always got nauseated and dizzy when the day begins, and though it lasts for a few hours, it goes away, leaving some killer headaches behind. Sometimes he vomits, but that's rare.

And today's apparently no different. As if to mock him, his skull gave a painful throb, and he closed his eyes, rubbing his temples. It didn't help. If anything, it made it worse. He groans, catching Cross's attention.

"Is it your headaches again?" It was a rhetorical question. They both knew the answer to it. So, why did he ask it again?

"Yes." He opens his eyes again to see them turning into the parking lot of the school. He sighs in relief, already wanting to get this day done with.

Cross parks and shuts off his old Chevrolet truck. He had found the car in the dump some years ago and found in surprisingly good shape. Some parts were missing, and some needed to be replaced, and it could've used a new coat of paint, but Cross said it was perfect. He spent the year fixing it and adding things on with his classmate Sci's help. He gave it a new coat of black with some white accents and it looked good as new. He's been driving them to school in it since then, as they both live far away.

Sometimes, Nightmare wonders where he would be without Cross.

Heh. Probably dead.

Years back, when they were both in middle school and they never knew each other, Nightmare was severely depressed. He was the outcast of the class and everyone hated him. He sat alone during lunch and was bullied for everything he liked. Reading, drawing, learning, everything. One day, he finally had enough. He had gone to the bathroom and planned to kill himself by hanging himself in a stall with a rope he stole from the theatre kids. He had had the rope in a noose and around his neck. All he had to do was jump. And he did, at the same time hearing the door slam open and a kid, who was a little too late, screaming no.

He had choked, suddenly regretting his decision. He didn't want to die. He had screamed in his mind for someone to help him, but nobody came. As his vision darkened, he heard voices shouting. And then he was cut down, falling into a gentle hold. He had gasped, and gasped, and gasped, but his vision had continued to darken; he was passing out. The person who had held him—was it a monster or a human? He couldn't tell—increased their grip.

"It's going to be okay," They said, barely concealed fear in their voice. Distantly, somewhere back in his mind, he had felt guilty at putting this person through this. Though, at front of everything he had felt nothing but muted things. "You're going to be fine, and we'll become friends like I planned we would at lunch."

A distant surprise, and happiness. The person had continued, "But you gotta—you have to—you have to hold on, okay? Stay determined, okay?"

The person was asking for a promise he wasn't so sure he could keep. But...they did say they wanted to be friends, right? All he ever wanted was a friend, just one. Someone who understood and protected him. Someone who laughed with him instead of at him. Someone who was the opposite of him. Someone like...like...where was he again?

He had tried to give a slight nod, showing that he was going to stay, but his head felt too heavy. Before he could attempt again, he blacked out.

He had woken up at a hospital later. His first visitor was Cross, and they sat and talked, learning everything about each other. Cross never mentioned his suicide attempt, not directly at least, but he revealed that he had been the one to find Nightmare. Nightmare, in turn, told him everything about school. They were the best of friends by the end of that day and stayed like that ever since.

Cross continued to monitor his depression, which never fully went away, so casually, it seemed like it was just something every friend does. He would be there for the bad days and encourage him through a normal day that seemed to go bad. With Cross's help, he also learned to ignore everyone, and they soon got bored with no reaction. The two gained a few friends who transferred and felt the same as they did. Nightmare grew happier every day, and Cross stayed with him until now, where the bad days happen very rarely.

Cross was the best. And he chose Nightmare to be friends with, out of hundreds of other kids. For that, Nightmare is eternally grateful. And extremely flattered.

"Nightmare? Earth to Nightmare! Are you going to sit in my car and skip school all day, or do I have to drag you?"

"Huh?" Nightmare blinks, looking up to see Cross with his backpack on and Nightmares in his hand and an eyebrow bone raised. He seems to have been waiting a while for Nightmare to react.

The other eyebrow bone joined its twin. "So...is that a yes?"

Nightmare shakes his head. "No, no. I'm good." He climbs out and takes his pack from Cross, who closes the door and they walk to the doors. "Just got lost in thoughts for a minute."

Cross chuckles. "Good. Because I couldn't drag even if I wanted to," His teasing smile appeared on his face, "you'd be too heavy."

Nightmare gave him a dry look. "I'm a skeleton. You're a skeleton. We're literally nothing but bones and magic. How could we be affected by weight?"

"You just need to ruin my fun, don't you?" Cross pouted. Nightmare would be lying if he said he was impressed.

"Yes, I do. It's my life mission. What I was born to do. What I was chosen to do. I must—"

"Okay, okay! I get it. Stop."

* * *

_He stands in the shadows, waiting._

_Mortals shivered under his stare, not knowing what was wrong as they could sense him but not see him. To them, he was but a feeling of foreboding. A chill that haunts them for days. Oh, how wrong they were. But they can't understand. Their flimsy pathetic brains couldn't begin to process his existence._

_He snorts. Mortals are so weak. He has no clue how any creature could be this oblivious and stupid. But he has to tolerate their existence. He has to—_

_There._

_He senses it the moment it comes closer. The aura of someone he knew once a millennium ago, still as dark and negative as it was before. The aura draws closer, and he sees the 'mortal' at last._

_He looks the same as ever. Good._

_He smirks. The time has come at last. His...friend...is ready at last._

_Let the die be cast, and the game begin._

* * *

The morning passed by slowly.

The teachers kept bringing up Halloween, trying to get students in the mood why they themselves didn't care for the holiday. Horror, another friend of Nightmares, threated to cut the third teacher who asked him if the blood from his head wound was a costume and was now spending time in detention after school.

"Honestly Horror," Cross shakes his head at Horror as he grumbles about his detention, "If you didn't let your temper get the best of you, you wouldn't even be in detention. It's your own fault!"

Horror glares at him. "Just shut up and eat your lunch."

Nightmare glances down at his own lunch. A Mystery Meat 'Special'. Yum. He sighs in disappointment, knowing his appetite will not let him have it without a few complaints.

"I would," Cross says, looking disgusted at his lunch. "but I don't think this is too edible."

"Well, I'm not giving you anything this time."

"C'mon! Why not?"

"It's your punishment." Now it was Cross's turn to glare at Horror.

Nightmare glances longingly at Horror's lunch. It looked so good.

Horror had started taking cooking lessons about three years back, and he was instantly drawn to it. He was good, too. It just the three years, he could make all his friend's mouths water in anticipation, even though they were all skeletons. He also made all of his own lunches, but he wouldn't make any for his friends, no matter how hard they tried to get him too. So, they had to suffer the school lunches.

It didn't really bother Nightmare, but it bothered Cross immensely. He complained about it almost every second of every day. Honestly, Nightmare didn't understand where he gets this energy to complain in the first place.

"Heya, Nightmare!" Nightmare turns at his name, coming face to face with another one of his friends, Dust. Behind Dust was their newest member, Killer. He was the new kid at the beginning of October, and his black streaks on his face made him fit into Nightmare's group just fine. Dust and Killer sits down on the remaining spots beside Horror. He glances at the other two and smirks. "Are those two arguing about food again?"

Nightmare smirks in return. "They're being idiots."

"Hey!" Horror and Cross exclaim in unison, making them glare at each other again. Nightmare was the first to laugh, trying to muffle it with his hand. Then Dust joined, then Killer, and soon enough all of them were laughing.

The bell rang, interrupting their fun. They all groaned, and reluctantly, they joined everyone in rushing to their next class.

* * *

_"Are you sure?" The skeleton mortal says, shifting in the dark that engulfed the room when he entered. It makes him smirk. "It's just a bit...sudden, is all."_

_He fakes a smile; not that the mortal would notice. "I'm quite sure, Principal Papyrus. But if you don't want too..."_

_"No! No, it's fine," The mortal says, waving his hands all over the place. "They're all bright students, so I'm sure it would be fine!"_

_"Excellent!" He says with fake cheerfulness, clapping his hands once. "Then you should call them, hmm?"_

_"Yes, yes! I'll do that right now." He watches hungrily as the mortal picks up the phone and presses one button. The mortal takes a breath, probably to help him calm down. "Could Nightmare Joku, Cross Jakei, Horror Npc, Dust Streblow and Killer Rahafwabas come to my office, please?"_

* * *

"Uh...what?" Cross says intelligently, staring at the ceiling. The rest of the class had paused as well, and stares at him, Nightmare and Killer.

"You've been called to the office, Mr. Jakei, along with your friends." The teacher, Mrs. Mathison, says, in a slow tone you put on for children.

Cross raises his brow bone as if to say _'Oh really? I had no clue.'_.

"Get your stuff and go, please."

Nightmare rolls his eyes. It was obvious what they had to do, but it seems the teacher thought they were all five-year old's mentally.

The three didn't protest, though they wanted to make a comeback, hoping to avoid trouble. When they were in the hallways, Cross and Nightmare started snickering. Killer just watched them, ever the quiet one.

"Okay, okay," Cross says, trying to calm down. "so, why were we called to the office?"

Nightmare hums. "It depends," He says, eyeing Cross slyly. "what did you do?"

Cross gasps, looking deeply offended. "What did I do? Me? I would never!"

"Well, if it wasn't you, then who was it?"

"You."

"Why I never—"

In no time they reached the office, meeting Horror and Dust. Before they could ask, Nightmare shook his head, answering that they didn't know why they were called. They all stand there, staring at the door, waiting for it to magically open.

"So," Nightmare says, taking initiative. "we all ready?"

"Yep."

"I suppose."

"It's not like I have a choice, right?"

"Ready as I'll ever be."

"..."

Nightmare grabbed the doorknob and turned, opening the door.


	5. A/N: UPDATE

Heya, I know it's been a long time since I updated this, but I wanted to make sure people knew why. I'm currently trying to focus on my other story, Kingdom Come. When that story is done, I'll work on this one, although that won't happen for a while. Another reason is that, as I looked back on this, I started to hate what was written. I have improved in my writing and I want to rewrite this story to fit my abilities so that I can work on it happily. That is all. I'm mostly writing this so that I don't have to delete this story and make a whole new one when I decide to publish it again. Any questions or concerns, please ask me in the comments.


End file.
